Has he ever said, "I'm really not that into you"? That's one good way to tell. Has he ever said, "Ew," when you suggested going out? That's another good way.

But seriously -- the best way to tell is to follow your gut. If it's telling you he's not interested, then he's probably not interested. We all have a tendency to downplay or deny what good sense tells us, particularly when it comes to matters of the heart. And who can blame us? No one likes rejection. But rejection is a part of life, and the gut is a smart cookie, so listen to it.

On the other hand, some of us are more neurotic and self-doubting than others, and we've learned to distrust our guts because although they are smart cookies, they are also filthy liars sometimes.

So now that I have basically contradicted myself, here are some things guys do when they aren't that into you. Most of these are subtle because dudes tend to avoid confrontation, especially with the opposite sex. But the signs are there if you pay attention.

A guy who isn't into you:

- Doesn't call when he says he will. He'll call, but a few hours or even a few days late. He got hung up at work, or fell asleep, or was kidnapped, or woke up in Peru. Sorry about that, he'll say. Bullhockey.

- Uses the excuse "I've been really busy" a lot. Yeah, we're all busy, but we find time for the things that are important to us. No one ever says, "Man, I was so jammed up today I didn't have time to breathe."

- Changes the subject when you say gooey things to him. "I really loved being with you last night," you'll say, and he'll answer, "Yeah, hey, did see that kid in the balloon thing on the news? That was nuts."

- Avoids doing things with your friends or family. Guys don't necessarily enjoy hanging out with your friends or family, and won't do it if they know there's no future with you. They're also afraid that your loved ones will spot their disinterest a mile away.

- Becomes selfish and lazy in the sack. It's hard to hide much when you're buck naked and doing nasty things to each other's bodies, so this is probably the easiest time to decipher your man's real interest -- or lack thereof. Is he suddenly unwilling to do certain things in bed that were once okay? Has he become predictable and rote? Does he avoid eye contact? Bad signs, all. Heed them.

I'm hoping that your guy does none of these and is as wild about you as he ever was. After all, I may be a Wise Ass, but that doesn't mean I don't care. I do. And I want you to be happy. So if your guy isn't into you, I'm sorry, but remember this: it's his loss. Move on and find someone who will appreciate you.

Good luck.

Want a second opinion? Check out this post from my esteemed colleague, Mr. Panama "Girls' BFF" Jackson. He's nicer than I am.